Scotland's Public Health Minister Michael Matheson has backed calls for a pre-9pm ban on TV adverts for food and drink high in fat, sugar and salt.

He has now written to Health Secretary Andrew Lansley urging a UK-wide ban.

Mr Matheson's support for a pre-watershed ban follows a School Food Trust poll that revealed 65% of parents would welcome it.

The survey also showed:

69% of parents agree they could do more to make their child's diet healthier

72% have purchased chocolate, sweets, crisps and sugary drinks or cereals because they were pestered by their child

87% would like to see healthier children's menus in restaurants

79% say there should be minimum nutritional requirements for food offered by any organisation looking after children

Advertising to children is already subject to strict rules.

The British Code of Advertising prohibits advertising aimed at children that is likely to:

result in their physical harm

actively encourage them to make a nuisance of themselves to their parents

actively encourage children to replace main meals with confectionery or snack foods

The Consumer Protection from Unfair Trading Regulations 2008 also prohibits advertising that directly encourages children to buy advertised products or persuade their parents or other adults to buy advertised products for them.

In 2007, Ofcom introduced new regulations to restrict advertising of food and drinks that were high in fat, sugar or salt, during children's television programmes or programmes considered to attract a lot of child viewers.

However, despite the introduction of the advertising restrictions, Newcastle University recently revealed that this has had no effect in reducing children's exposure to adverts of this type.

Comparing a period of advertising six months before the regulations were brought in against a period of advertising six months after the regulations had been fully implemented in 2009, the university found that children were still exposed to the same amount of adverts for less healthy foods.

The university did find that nearly all the adverts shown during children's television programmes complied with the regulations, but the problem was that children do not just stick to watching children's television programmes.

In fact, the percentage of advertising of foods considered to be less healthy and seen by children had risen from 6.1% to 7%.

Backed by the Schools Food Trust, parents, and Scotland's Public Health Minister, the UK government is likely to come under increasing pressure to act, and further restrictions could be on the way.